Posted
by
kdawson
on Friday July 17, 2009 @09:23AM
from the mehr-licht dept.

Mike writes "Researchers at Korea's Advanced Institute of Science and Technology recently announced a breakthrough in OLED technology that reduces the ultra-thin lights' energy consumption by 75%. The discovery hinges upon a new method of creating 'surface plasmon enhanced' organic light emitting diodes that boast 1.75 times increased emission rates and double the light intensity." OLEDnet notes: "The finding was published in the April issue of Applied Physics Letters and the June 25 issue of Optics Express. It will be also featured as the research highlight of the August issue of Nature Photonics and Virtual Journal of Ultrafast Science."

Yep, even a 100W standard bulb in a small room is much too dark compared to outdoors. I'd love to have more powerful lighting tech available, but not at reduced output -- at the same output or better.

Where this will really make a difference though, is in mountain bikes --- it currently costs around £350 for a reasonably high-end lightsource for bikes, and even then, the high-end well-reviewed stuff just sucks for any serious riding in the dark. Riding in the dark isn't just necessary in winter -- it

My computer room is intentionally dark. The newly-installed solid red oak floor is stained black, the walls are a dark, flat olive drab, and the ceiling is a matching shade of dirty brown. There is a black curtain over the room's solitary window. I cover all of the blindingly-bright blue LEDs on my electronics with red electrical tape to dim them down.

Curses to you and the other light-seekers, and likewise to your reflective e-ink displays. Everything I need to see lights up by itself already.

Indeed the TFA mentioned nothing. I had the same thought as you, specifically regarding blue OLED. They have the shortest lifespan. I would figure though, if they are 75% more efficient, that mean far less energy being pumped through the device and therefore (though possibly incorrect) less strain on the organic structure and slower breakdown.

I've heard that blue is now rated for 30k hours before they hit half brightness. Not so great for continuous lighting, but great for occasional lighting, monitors and TVs. If it is the intensity that hurts, hopefully they'll put in some brightness limiters to stave off premature death from users that just max out the brightness, I don't know why, do most people have glaucoma?

But what *I'd* really like to see is some real advancement in photon-reflective display technology rather than emissive. Our eyes are evolved to primarily observe light reflected _OFF_ of other objects, not photons flung straight into our eyes from some source, and in my experience it is *FAR* easier to observe something for an extended period of time that is being lit by surrounding light than it is to study something that produces its own. I think it may have something to do with pupil dilation... bu

There's not going to be a big difference between a photon flung straight into your eyes and one that's reflected off something.

A red photon of X wavelength of the same energy will still be perceived the same whether it was reflected or not.

Now the difference could be in the spectrum.

The light from LEDs or CRT phosphors are more likely to be rather "narrow band" in spectrum. Basically the colours are created by having 3 narrow "mountains" of differing heights corresponding to Red, Green and Blue.

Whereas white light (or light from blackbody sources) reflecting off various stuff is more likely to generate wider "mountains".

I'm not sure if this will cause a perceivable difference in the generated image on screens. But I'm pretty sure there's a difference if you use the light for illuminating stuff e.g. a very narrow band red pigment lit by a real white light source will appear red, but could appear black under "white" light that's generated by red+green+blue LEDs (which is one of the reasons why white LED flashlights use phosphors).

The spectrum might be in there for some reason, although IMHO when reading a book, it's pretty much black text on a monochrome piece of paper that I'm looking at anyway.

Technically there indeed won't be much difference whether the photon was sent directly or indirectly into the eye, but I think the difference in perception here comes from what's going on *around* the screen.Eg. when a cloud passes by, the surrounding light-level diminishes by a factor x, your eyes adapt (slightly) to the overall changed con

Not sure whether you're being funny or not =),but I do have considered digging out that 'coated piece of perspex' I used to have hanging in front of my Amiga monitor... It sort of increased contrast, reduced glare and supposedly helped against flicker. Problem is, once I open up that treasure-chest I'll be wanting to get my Amiga(s) back online etc and before you know it I'll have lost days if not weeks purely on nostalgia. (**)

(** wonder if I'd get SPOT back online somehow.. Anyway, most likely the hard-di

How is that "utterly and totally wrong"? The eye is extremely weakly sensitive to polarized light, producing an extremely faint effect that requires practice and concentration to see. Try not to overreact.

1) One other difference is the image/light from many screens tends to flicker.Many CRTs will flicker - the refresh rate is typically from 60-85Hz. The LCD panel backlight might also flicker a bit too. I'm not sure about the OLED tech.

For the people who say you can't see the difference, just wave your hand in front of the screen. Then go out in daylight and wave your hand. Notice a difference?

Alternatively, look at the screen from the side of your eye - for many people the image will not appear to be as "sta

Apparently with OLEDs the blacks should be much blacker than LCD blacks. But I suspect they're still going to be blindingly bright.

Why would an OLED still have bright blacks? The reason LCD's don't do black well is because the pixels can't totally block the backlight. OLEDs have no backlight so a black pixel should not emit any light.

It's just 75% increased emission rate, not 75% less energy. Continuous wave photoluminiscence doubles, though, according to the article. 75% more efficient would've been four times the output. So not THAT great, but still rather awesome.

Isn't "75% more efficient" only 75% more output? Efficiency is usually listed as lm/W which clearly would indicate 75% more efficient is 75% more lumens. On the other hand, "75% less energy" is 4 times the efficiency.

Sony and LG both have plans to release OLED TVs within the next year. The new Sony TV is planned to be 27 inches, so large screen OLED displays could be on the horizon although it's probably a few more years out.

(1): "a 75% more efficient light" would mean an increase to 175% or original, a factor of 1.75 times better.(2): "reducing by 75%" means a factor of 4 better.(3): "increases photoluminescence emission rates by 1.75 times" means a 2.75 time increase, a factor of 2.75(4): "increases light intensity twofold" is a factor of 2.

Seven times more efficient according to recent article [nytimes.com].
Its fascinating you can teach an old dog new tricks with sufficient economic incentives. I welcome the competition among old and new technologies.

"The method using surface plasmon represents a new technology to enhance the emission efficiency of OLED. It is expected to greatly contribute to the development of new technologies in OLED and flexible display, as well as securing original technology," --Prof. Choi

Doesn't that just sound like something out of the Alpha Centauri tech tree?

Light emitting diodes tech is one of my favorite. It and all the inventions which derive from it, makes life look and feel as though we're truly in, "The Future" as I ima

If we need to use whales for this then that is fine as long as we start a breeding program to accelerate the replacement of the culled whales. Maybe we could harvest eggs and sperm from harpooned whales, then create embryos and mature them in an artificial uterus, then release them back out to nature to grow where they could be harpooned and the cycle would continue and we could increase the number of whales in the oceans exponentially.

Why do we always return to picking on the whales? What did the whales ever do to warrant this? Whales are cool!I say lets replace all usage of whale blubber to using people blubber instead. There are plenty of useless people wandering about everywhere. A few here and there won't be missed. We can start with rounding some up in the halls of congress.

I say lets replace all usage of whale blubber to using people blubber instead. There are plenty of useless people wandering about everywhere. A few here and there won't be missed. We can start with rounding some up in the halls of congress.

You don't have to kill them, just give them all free liposuction. Win-win.

I would think the usefulness of these OLEDs would be more for brighter (daylight readable) electronic displays than for hugging trees and crunching granola. Eco friendliness is not the only reason to conserve power; consider for example extended battery life as a more tangible benefit.

OLEDs might be the future for most displays (has the problem of a low blue life span been solved yet?), however when it comes to competing with direct sunlight all they can do is try to outshine it - not a competition any technology so far has won.

Transreflective LCDs, where the backlight transmits its own light but also reflects incoming light, are much better solution there. And for mostly static displays of course ePaper which will hopefully get faster pixel switching time and colour in the future.

Vacuum deposition is a reasonably common industrial process. Not absolutely trivial(high-vacuum pumps aren't cheap, and I'm sure maintaining the seals on a high-throughput system with a vacuum stage is a pain in the ass); but hardly more difficult than any of the other tricky processes that we run in massive volume every day.

I can tell you that maintaining a high vacuum seal is simple. Orings are amazing things, and the physics that goes along with them is astonishing. That unassuming little black ring really is quite amazing. Forget holding a vacuum; properly designed, they can stand up to 100x atmospheric pressure against a total vacuum and not break a sweat. I'm a scuba diver, and the orings on my scuba tank yoke valve hold up 200 bar, which makes the pressure difference between normal air pressure and a vacuum look like the breath exhaled from the mouth of a sleeping newborn.

Forget holding a vacuum; properly designed, they can stand up to 100x atmospheric pressure against a total vacuum and not break a sweat.

That's all well and good but you're not dealing with a setup where a single dust spec will ruin everything. Ultra high vacuum systems don't merely need to hold the pressure, they need to ensure that nothing ( not even slightly too many helium atoms ) can diffuse into the system. To get a basic idea of what is needed of these systems, leaving fingerprints is an absolute no-go since the low pressure will cause the water to evaporate contaminating your setup. Also forget o-rings made out of rubber or any other polymer based material. They are too porous and allow stuff to diffuse through them. The o-rings used in practice for helium tight vacuum systems will be made of a metal alloy that has been carefully picked to be soft enough that you can squeeze it slightly (but not too much ).

Essentially while your scuba gear may be holding a very large pressure that's not quite the same thing as ensuring that it does not have a single atomic scale leak. It's a bit like comparing a fog-horn to a powerful amplifier and then proclaiming the amplifier must be primitive since the foghorn is louder.

...I hope this isn't like some of those other "eco friendly" solutions...

Nowhere in either article is there any claim towards being eco-friendly. Neither is the word "green" in the articles, so I am quite at a loss as to why you're off on this tangent. The only claim that might be considered close is the 75% reduction in energy use, however that statement is leaps and bounds away from "It's green and eco-friendly".

Green? I hope these new OLEDs are more than just green, but red, blue, orange, white.

The chance for ecological whaling passed a long time ago, when people decided that it wasn't important to kill whales at a rate lower than their reproduction rate.

Now, due to the errors of the past, we are left with the alternative to stop whaling altogether, or have no whales in the future. Most sound minded people realize that having no whales in the future means whaling will stop altogether, so it's a matter of stopping whaling either way. I vote we stop whaling now, so th

Many vapor and physical deposition processes in semiconductor manufacture take place in a high vacuum. Making OLEDs probably already requires a vacuum at one stage for such deposition. I would say the efficiency issues with this process hinge on cost, not energy, and even that seems quite manageable.

Sounds like a great new technology but I get frustrated when product seems to take forever to get to market.

It's important to keep perspective on news items like this as "research results" rather than "products." That misunderstanding takes the fun out of a great spectator sport.;-) Sometimes results out of the lab are immediately applicable, more often they take a quite a number of years to work out the practical kinks. E.g. this recent article on silicon for photo detectors in Tech Review [technologyreview.com] has a good examples of the kinds of problems researchers have to muddle through on the way from breakthrough to reality.

Sometimes results out of the lab are immediately applicable, more often they take a quite a number of years to work out the practical kinks

Besides being +1 insightful, you can replace "sometimes" with "almost never", especially on Slashdot technologies. I honestly cannot remember a SINGLE technology predicted here that I can actually buy yet. But I've only been here a few years.

OLED displays. Electronic ink such as used in the Kindle? All tech that has been reported for years on slashdot, and made it's way into our hands.

Tech happens all the time but we tend not to be as awed anymore when it has actually arrived because... well tech has moved on.

When OLED displays were first announced, they were REALLY amazing because LCD's of that age had problems enough with even lightening let alone doing proper blacks. Their viewing angle was also horrible so OLED's with their 180 degree vie

Many methods for organic device deposition make use of inkjet printing which is extremely low-cost and easy to do (I'm guessing roughly several square miles per day).

They're using silver nanoparticles. Silver isn't cheap, but in that quantity it's not a big deal. Possible improvements to this method include using a different nanoparticle material (but silver is the best for surface plasmon effects, except for maybe gold) and incorporating inkjet printing to avoid high-cost vacuum environments. I don't think an inkjet deposition method would interfere with surface plasmon interactions on the nanoparticles so we should still see good efficiency.

TFA didn't mention lifetime, and I figure that it's not a huge issue anymore for OLEDs. Another big advantage with using silver is that it isn't susceptible to photocorrosion (silver oxides do not form readily).

Another big advantage with using silver is that it isn't susceptible to photocorrosion (silver oxides do not form readily).

Hey, sorry for my ignorance, but I thought that silver is highly susceptible to photocorrosion - isn't it used in photographic (b&w) film, or photochromic lenses? I'd just like to know where the difference is, or just some more info.

Silver compounds (like what you have in your film) are not very stable because it doesn't like to oxidize. Pure silver (as is used in their nanoparticles) are the opposite - very stable in elemental form. The only element that's more inert than silver is gold AFAIK.

It should make sense: elements that easily form compounds are unstable in elemental form; elements that don't easily form stable compounds are stable in elemental form.

It would certainly be modestly more expensive than an otherwise equivalent process that doesn't require a high vacuum step; but vacuum deposition isn't exactly exotic. All sorts of surface metalizing processes use it.

Aside from that, there are applications(actually quite a lot of them) where being able to consume less energy at the point of use, even if you consume more energy overall, is quite valuable. For any "off grid" application(whether permanent, like your survivalist bunker in Montana, or temporary, like your macbook during a trip to starbucks) what really matters is how much energy your device is using now not how much energy it took to create. For that matter, any rechargeable battery is highly wasteful, since a fair bit of the charge energy will just be lost as heat; but having the energy where you need it is obviously valuable. This is the same reason why solar panels became valuable for specific off grid applications well before they reached the break-even point for lifetime energy cost vs. energy production.

Who's "we"? Rather, I spend the most I can afford on consuming less energy, and I'm not alone. Once you have an easy-to-read electricity meter in full view you change your behavior; I stopped lighting my garden and most of my house once I realized how much even my low-voltage and fluorescent fixtures consume. And I bet Prius drivers ride bicycles more than SUV owners. Some people give a damn, join the club.

So you don't know how much energy it takes to make a vacuum, but you pose that it might be more than the light will save? This kind of lazy false tree-hugging disappoints those who care and scares off those who don't.

Air pressure is roughly 15 PSI at sea level. The energy required to create a vacuum is roughly the energy needed to lift 15 pounds from the bottom of your vacuum vessel to the top of the vacuum vessel. Naturally, the exact amount of energy depends on the size of the vessel, and you'll probab